[HonkyTonkMan]

Interval training. Been around or decades - it's not some ancient Japanese wisdom.

Many sports call them Indian Runs, Shuttle Runs, Suicide Runs, Ladder Runs, etc.

[jimtorr]

Many sports call them Indian Runs, Shuttle Runs, Suicide Runs, Ladder Runs, etc.

When I was running track and cross country in Oregon in the 1970's, we called it Fartlek. It's a training method in use in Europe since the 1930's.